Crystal detector



Nov. 3, 1925. 1,559,723

- F. E. MANN CRYSTAL DETECTOR Filed Dec. 10, 1923 Clue: nu

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Patented Nov. 3, 1925. if;

A UNiTEDfsTA'ri-:s

PATENTA oFFIcEg l' FBEDERIGKE, MANN, or cIIERRYn-ALE, VIRGINIA;

' CRYSTAL DETECTOR.

Application filed December 10, 1923. Serial No. 679,692.

' new and use-ful Improvements 4in lCrystal Detectors, of which the following is a: specilication.

This invention relates generally to radio telephony and has speciic reference to the crystal detectors employed in conjunction with certain types of radio sets. The primary object of the present invention is to provide av crystal detector, broadly of the type shown and described in my copending application, Serial Number 675,676, wherein the same may be mounted within a radio set cabinet for imparting thereto the appearance offa radio set of the tube or higher pricedv type. l v v An additional object of the invention is to provide a crystal detector to be mounted within a cabinet, wherein vthe spring contact, or cat whisker as well as the crystal elements may be moved toward or away from each other, by means externally of the cabinet, and wherein extremely ine adjustments of the crystal elements may be ob' tained for thereby eii'ecting va very sensitive tuning of the radio apparatus with which the detector is associated. Yet another object is to provide incoin bination with the detector, means for allowing a clear vision to be had of the' adjustments of the spring contact and crystalelements with respect to eachother, for there'- by obtaining the proper tuning effect of the radio apparatus in a minimum'amount of time, A Y f L Vith the above and other objects in view as the nature of the invention will be'better understood, the sam'e 4comprises, the novel form, combination and arrangement of part-s hereinafter more fully described, shown in l the accompanying drawing and claimed.

In the drawing wherein like reference characters indicate corresponding ly modified form nf the present .llYltOlf v parts throughout Figures l and 2, and whereiny there is disclosed the preferred and a slight-.-

.Figure l is afragmentary frontfelevational view of a radio receiving set cabinet upon the interior of whichjis )disposed a` crystal detector constructed in accordance with theV present invention,

Figure 2is a similar view-of the interior of the cabinet fordisclosing more clearly 'the relative Vpositioning of the, present crystal` detector uponl the back `side of the front panel board vof said cabinet, and

Figure o through said panel boardrthecrystall detector in this' i'nsta-ncebeing provided with a modified means for yadjusting f the spring Contact or cat Whisker with respect lto the crystal contact element. j

Now having particular reference to Figures l and 2 of the drawing, there is shown a crystal detector adapted for disposition within-the cabinetoic' a radio set that is oonstructed generally in a manner similar to the detector shown in the above-mentioned co-pending application. That is, the device includes the spring/strip 10 upon the top side of which is disposed the holder 11 for the crystal carrying cup 12and-that carries at one lend a vertical post 16 within the slotted upper end of which Vis pivotally disposed-thearm '17 formed at its other end with a ball-shaped head. AsV in my cpo-pending application this head Ais `disposed between the .adjacent ends of a pair ofspaced parallel plates 20, the samebeing formed at this end with segmental spherical yopenings for this purpose and for establishing a uniarrn. Disposed for universalinovement between the other ends of the plate is the stem is' a longitudinal sectional View `versal connection ybetween the plates and l neath and atonelside of a. vertically arl anged oblonglfopening 28l in said fpanel ars.

.the face of the crystal element.

For allowing the spring and crystal coni tact elements to be more:A clearlyl viewed by.

the operator of the set a suitable formv of reiector- 291- is.:V4 disposed within the,A cabinet and atl a point directly behindf said-1 spring andA Ycrystal element.

Disposed for free-rotation throughlanropen.- ing in the paneli board' '271 at ai. point di rec'tly beneath' the free' end'of the spring stripl-(lisra shaft 30 upon' thelinner endxI of whichl` isieccentric'allyf disposed afdisk 311i the periphery offwhi'cli/ is alwa'ysi engaged@ by Y the free end'lofithefspring stripfrllOduev tothe factl that the-tendency ofthe springfstnip 1s to flex' downwardly.' l

vThe outer4` end: of? the sha-ft is equipped with a d`esirable=form of: operating knob/32 whereby' the` shaft may? beV easily 'rot'ated in the desired direction.. It willthuslbe seenthat; alten al rough adjustment ofthe spring contact with relation tok the crystal has been: obtained: by. moving the fingen piece -orkn'obiQSani extremely. fine adjustment between ther contacts may be procuredr by slowly! moving thexlnob. '82. inl the desiredf'direction thel movement of said knobl obviously Causin'g relatively slight movements offthe crystal elementsi InF-ijgure 3 wherein the. detectorconstruction is` id-:ntficalfwith` that showny in Figures l and@ with thelexcep'tionof the Icat whislrery carrying ands adjusting mechanism, the front panel board 27 offthea r-eceivingyset cabinetfis-:provideduponlthe: night) hand side ofthe. opening. 28 therein with ai circular shapedf opening-133:- within which is set: a

metal? plugrlla thatfissformed with ar central transverse openingfthat flares outwardly, at

its inner' end andsV that terminates ati its front. end" into .ae socket 3:5; Positioned within' this socket isV a; ballshalped head: 36

formed upon; a rod'l, thei-outeriend offwhich isf equipped@r with ai finger, piece or lrnobvSS while the inner .end` thereof isinturinedt at in af. direction. toward thefopening 28 in the' panelboartd 27 and; to 1 which is aittached, the.; spring contactorcat=,wl1isker notfsho'wn': Y l

Eor maintaining theballfshgaped head 36 withinztlie frontsoeketed? end ofgthefopening of the: plugft theref'isg prnvideda retaining plate 4dr-secured toa thee frontsidei of-.said plug 34 in any manner desirable. It-will therefore be seen that l have provided in this modified form of the invention, a highly novel and simplified form of universal support for the spring contact or cat Whisker of the present crystal detector, and in this instance it will also be noted that said spring contact,Y may be'- adj-#usted relative to the crystalv by thehand off' the operator and Athis without necessarily having to position Vthe hand: forwardly of the opening 28 n the panel buard 2'7"2 which might otherwise -Imar the-view of the contacts of the deiiector.

tion without departing from the spirit and scope of the appended,c laiInS ./.l l. j

Having thus described my inventiorn;V what L claimasf new and( desire to-secure Letters-Patent,-is. l y y y 1,.. A cnystal detector`v comprising aI panel having an openii'ig; formed therein, a support-ingfgbracket mountedonthe rear sdeof the panel. and' at onel side. of. theopeningna shaft rotatablyl mounted in the panel: atlthe opposite f side of the opening, and: projecting fromr opposite` faces/ of the paneh, ai., disc. ec-

centrically mounted on@ said; shaft im the iearof the panel, a spr-ingr stripfsecu'red at onexend tofthe supporting, bracket andhaving its opposite endengagingthe periphery of; the disc andnorlnallyfftensionedf in' engagement; therewith,l a. 'crystalY velement mountedon,thestrip.in thereafr, of the openingfin the panel,l a` spring;` contact movably .mountedion said supporting, bracket for engagement with anyY desired. portion of Vthe crystal; an operatingineans carried by'said spring conta-ct operable from, in frontof the panel forf engaging, saidl spring contact with, the crystal, saidr shaftfbeing. manually rotatable; from the front, ofthe panel4 for moving,saidfdiscfso thatthe crystalv` may be adjusted to vary` the tensionofv` the spring contactthereon. I

2.v A, crystal, detector comprising apancl having an opening formed'therein, a` supporting.. bracket` mounted. on thel rear side of. the panel and.y at, one.` side of.'` said,i opening, a springV strip mounted at one endL on said bracket,andprojectingacross the lower end.. of.v said;opening,r in the panel, means operable from the front. plate. of the panel. and mounted thereon'. for' engagingJ and maintainingsaid -vspringl;` strip funden' tension, and, operable-.for raising.; `and` lowering the freefend. thereof, a crystal'` element mounted onl the centrali portion j. of"` said? spring stripin the rear ofthe opening in saidpanel, and

that the Contact spring may be operated to engage the desired portion of the surface of the crystal element, said operating means being adapted to. effect a movement of the crystal toward or away from the contact spring to vary the tension of the spring on said crystal.

ture.

FREDERICK E.` ,MANN

In testimony whereof I aix my signa- 

